Effects of Ni on structure and mechanical properties of Al-Cu-Mn alloy

To study the effects of adding Ni on the tissues and mechanical properties of Al-5.0Cu-0.6Mn alloy, the mechanical properties of the alloy were studied by hardness tests, tensile mechanical tests and friction and wear tests, and the alloy microtissues were detected and analyzed by scanning electron microscope, laser confocal microscope and transmission electron microscopy. The results show that after adding Ni to Al-5.0Cu-0.6Mn alloy, the hardness and strength of the alloy are greatly improved, the frictional wear depth significantly reduced, and the comprehensive mechanical properties effectively improved, due to the reinforcement of Al₃CuNi phase precipitation and the enhanced phase particles well combined with the matrix being uniformly distributed in the alloy. When the added quantity of Ni is 0.3% (referring to the mass fraction), due to rather evenly distributed T phase (Al₂₀Cu₂Mn₃) and Al₃CuNi phase, the comprehensive performance of the alloy is relatively ideal, with HV hardness of 126.4 MPa, tensile strength 395.2 MPa, and friction and wear coefficient 0.12, respectively.